Page control and page control release for typewriters



Dec. 4, 1951 V YUTANG 2,577,062

PAGE CONTROL AND PAGE CONTROL RELEASE FOR TYPEWRITERS Filed May 5, 1950FIG].

LIN YUTANG (la ma- HIS ATTORNEYS.

Patented Dec. 4, 1951 PAGE CONTROL AND PAGE CONTROL 'RELEASE FORTYPEWRITEI QS.

Lin Yutan g, Cannes, France Application Ma /3, 1950, Serial No. 159,723

This invention relates to a page control and line indicating device fortypewriters. It relates more particularly to a device constructed andarranged to guide the typist by showing how much of the page has beentyped and further to indicate when the bottom of the usual typing areais reached by making it impossible for the paper platen to turn farther,unless manually released. I

Devices of the type embodying the invention may include an indicatorhaving a dial and a pointer which are moved relatively in response tothe rotation of the platen of a typewriter as it advances a sheet. Theindicator is suitably calibrated to indicate the number of lines of typein the typing area of a sheet, this calibration being related to thediameter of the platen so that advancing of the sheet by rotation of theplaten also advances the indicator.

In the conventional typewriter, the diameter of the platen is such thateach complete turn of the platen advances the sheet adistance equal toabout 26 single spaced lines of typing. The average letter size sheetof-paper is of sufficient size to receive 67 to 68 lines of single spacetype. The usual typed portion of a page occupies about 52 lines, singlespaced, or 26 lines, double spaced. so that two complete revolutions ofthe paper platen will cover the usual typing portion of a page. controldevice, the indicator is calibrated to make slightly less than onecomplete revolution for each two turns of the paper platen. At thistime, further rotation of the indicator and of the paper platen isprevented by means of a suitable catch which may be, however, manuallyreleased to permit additional lines to be typed on the page or to permitrelease of the platen for removal of the page and resetting of theindicator to zero.

If desired, the indicator and control device may be provided with a twostep catch or look which is related to, for example, letter size orlegal size sheets so that the indicator can be set at will to indicatethe end of the typing areafor either type or length of sheet or page. l

The indicator, of course, indicates the number of lines that have beentyped and also conversely the number of lines remaining to be typed onthe sheet. It can, if desired, be providedwith an audible warning deviceas well as the automatic stop and it can be connected with otherelements of the typewriter such as the page release bar for automaticresetting as the paper is inserted or withd wn m the typewriter. a Y aIn the preferred form of' indicator and 7' Claims. (01. 197-139) For abetter understanding of the present invention, reference may be had tothe accompanying drawings, in which:

Fig. l is a view in plan of a portion of the typewriter including a partof the platen supporting frame and the indicating and control deviceembodying the present invention attached thereto Fig-2 is a front viewof the indicating and control device and a portion of the paper platenand the paper release lever and bar;

Fig. 3 is a front view corresponding to Fig. 2 with the indicating dialremoved from the indicating and control device;

Fig. 4 is a view in section taken on line 4-4 of Fig. 3;

Fig. 5 is a view in section taken on line 5-5 of Fig. 1;

Fig. 6 is a front view of a modified form of control and indicatingdevice mounted on the frame of a typewriter, a portion of the platen andcontrol knob also being shown;

Fig. '7 is a front view of the indicating device with the dial andpointer removed therefrom showing a modified type of stop pawl in oneposition;

Fig. 8 is a view of the device of Fig. 6 showing the stop pawl inanother position; and

Fig. 9 is a fragmentary view partly in section of; the two position stoppawl illustrating details of construction. i

The invention will be described in connection with a conventionaltypewriter. Only a portion of the typewriter including'a part of theframe and the paper platen is illustrated in the drawing for the otherelements of thetypewriter do not form a part of the present invention.The indicating device I0 embodying the invention may be mounted upon oneside ll' of the frame of the typewriter, this frame also supportingrotatably the paper platen roll 12 which is provided withthe usualcontrol knob I3 connected by means of a shaft I4 to the roll.

The indicator I0 includes an annular or ringlike dial l5'which issecured to the frame member I by means of a tongue or lug IS to preventrotation of the dial. The center of the dial is open to display aheart-shaped cam H which is supported on the front of a generallydisc-like member it which is keyed to a shaft l9 rotatably mounted in aplate 20 fixed to the front of the frame member II.

l The shaft In carries behind the member l8 a bevel gear 2| which mesheswith a smaller bevel ear 22 rotatably mounted upon a shaft can ried bythe frame I in a manner to be described. Fixed to the back of the bevelgear 22 is a thin spur gear 24 which meshes with a thicker spur gear 25fixed to the shaft l4. Because of the geared connection between theplaten |2 through the shaft l4 and gears 2|, 22, 24 and 25, the disc I8is caused to rotate a little less than one complete revolution for eachtwo revolutions of the paper platen. The two turns of the platen |2ordinarily are sufficient to move the page or sheet of paper through adistance equivalent to about 52 lines of single space typing or 26 linesof double space typing. I v

The disc member I8 is provided with a tooth or shoulder 26 whichcooperates with a pawl 21 pivotally supported by a pivot pin 28 on thefront of the frame member I. The pawl 2! is normally urged against theperiphery of the disc l8 by means of a spring 29 so that the rotation ofthe disc member I8 is limited to slightly less than one completeclockwise revolution from starting or zero position. The tooth of thepawl is disposed on top of the tooth 26 when the point of theheart-shaped cam is at zero position on the dial l5, as shown in Fig. 2.

With the above-describedrelationship of parts, if a sheet of paper isinserted in the typewriter and adjustment made for the heading of thetyped matter and the indicator set at zero position, typing may continueuntil the disc member l8 has rotated clockwise from the position shownin Fig. 2 and the tooth of the pawl 2! engages tooth or shoulder 25. Atthis time, the platen |2 as well as the disc i8 is locked againstfurther rotation in a direction to advance the sheet or page.

The page or sheet is released from the typewriter, or additional linescan be typed on the page or sheet by means of a release for the pawl.The release mechanism includes a key 30 which is guided for up and downmovement in a pair of guide plates 3| and 32 fixed to the frame The keyincludes, as shown in Figs. 4 and 5 a guide bar 33 which is straddled bythe bifurcated end 34'of the pawl so that downward movement of the keyrocks the pawl counterclockwise and lifts it out of engagement with thetooth or shoulder 25. The key also includes a second parallel guide bar35 which is provided with an inclined cam portion 36 disposed behind andin alignment with the axes of the gears 22 and 24.

As shown in Fig. 5, the gears 22 and 24 are rotatably mounted upon ashaft 23 which is slidable in a bore 38 in the frame II and also in ahousing 39 on the right-hand side of the frame. The housing 39 includesa cup-shaped member 40 threaded into a collar 4| on the side of thehousing and encloses a coil spring 42 which bears against a collar 43fixed to the shaft 23 so that the'shaft 23 is normally urged to the leftto engage the gear 22 with the gear 2|.

The cam 36 is used to disengage the gear 22 from the gear 2| by engaginga push pin 44 which is slidably mounted in a bushing 45 in the lefthandend of the bore 38 and engages the lefthand end of the shaft 23. Withthis arrangement, when the key 30 is depressed, the pawl 27 is releasedfrom the shoulder or tooth 26 and the platen I2 is uncoupled from thedisc l8 by disengagement of the gears 2| and 22. The width of the gear25 is such that the gear 24 remains in mesh with it despite axialdisplacement of the latter.

. Besetting of theindicator is alsoaccomplished.

by means of the key 30. The resetting mechanism includes a lever 46supported on a pivot pin 41 projecting from the frame The lever 46 has asharp pointed tooth 48 thereon for engagement with the periphery of theheart-shaped cam ll. Inasmuch as this cam has both loops thereof formedas a spiral, engagement of the tooth 48 with the cam in any positionwill cause the cam to rotate to bring the point into the valleybetween'the two loops of the cam, thereby returning it to zero. Pressurefor the resetting of the cam I9 is provided by means of a pin and slotconnection 49 between the left-hand end of the lever 46 and the guidebar 33, as shown in Figs. 3 and 4. Thus, the operation of the key firstreleases the disc and cam H for free rotation, and continued downwardmovement of the key 3|! causes rotation of the disc l8 and the cam I1back to zero position.

While in most instances the provision of a separate key 30 is mostsatisfactory for the operation of the indicator, it will be understoodthat the key may be connected to the page or sheet release lever 59 sothat upon operation of this lever, the indicator is released and resetpermitting the sheet to be inserted or withdrawn from the typewriter.

The device is susceptible to further modification in its details. Forexample, as shown in Fig. 6, the cam 59 may be concealed behind adisc-like plate 60 which is rotatable relative to the ringlike dial 6|and bears a pointer 62 thereon for cooperation with the dial 6|. Also,the pawl mechanism may be modified to render it completely ineffectivewhen the indicating and control device is not needed, or to causestoppage of the platen when typing sheets of different length. A typicalpawl mechanism for this purpose is illustrated in Figs. 6, '7 and 8. Thepawl may consist of a piv otally mounted lever 33 like the pawl 2'!described above, differing in that it is provided with an arcuate combportion 64 provided with a pair of notches 65 and 55 in its outer edge.The outer end of the pawl member is provided with a pivot pin 67 behindthe pawl tooth 68. The pin 81 supports an inverted V-shaped member 69having a pawl tooth ID on the end remote from the pivot.

The V-shaped member is provided with a slot ll near its apex to receivea flattened zigzag spring 72 which normally urges a pin 73 in the slottoward its lower position. The pin may be pro-' vided with a suitablehead or knob 14 to permit it.

to be pushed up the slot when adjustment of the pawl 16 is to be made.Thus, when the pawl tooth 10 is to be retracted, the pin 73 is engagedin the platen 17 before it has been turned through two completerevolutions.

The whole pawl assembly may be rendered in effective by means of a lug18 on the inside of the typewriter frame '19 over which the projectingpin 13 can be hooked to retain both of the teeth of the pawls out ofcontact with the periphery of the disc member '16 against the tension ofthe spring 83 so that the indicator can continue to' rotate as long asthe paper platen is turned to advance the sheet.

From the preceding description, it will be ap-- parent that a device-hasbeen-provided which is capable of stopping the rotation of the paperplaten before the sheet has been advanced from beneath the type bars andalso which indicates the number of spaces for typing remaining on thesheet.

It will be understood, of course, that there may be some changes in thestructure and relationship of the elements making up the control andindicating device, and, therefore, the forms of the device describedabove should be considered as illustrative and not as limiting the scopeof the following claims.

I claim:

1. In a page control and line indicator for typewriters having arotatable platen; the combination of an indicating dial, a pointermember adjacent to said dial, drive means interposed between andconnecting said pointer member to said platen for rotating themsimultaneously, a releasable stop member to limit rotation of saidpointer member to less than one complete revolution, means fordisconnecting said drive means to disconnect said pointer member fromsaid platen, means for returning said pointer member to an initialposition relative to said dial, a key for successively actuating saiddisconnecting means and said returning means and means connecting saidstop member to said key to release said stop member upon actuation ofsaid key.

2. In a page control and line indicator for typewriters having arotatable platen mounted in a frame; the combination of a dial mountedon said frame, a pointer member adjacent and rotatable relative to saiddial, gearing connecting said pointer member to said platen forsimultaneous rotation, a releasable stop member to limit rotation ofsaid pointer member to less than one complete revolution, a part of saidgearing being displaceable to disconnect said pointer member from saidplaten, means for rotating said pointer member to an initial positionrelative to said dial, a key for displacing said part and thereafteractuating the means for rotating said pointer member to said initialposition and means connecting said stop member to said key to releasesaid stop member upon actuation of said key.

3. In a page control and line indicator for typewriters having a platenrotatably mounted in a frame; the combination of an indicating dialmounted on said frame, a pointer member rotatably mounted adjacent tosaid dial, releasable drive means connecting said pointer member to saidplaten for rotation therewith, a heart-shaped cam fixed to said pointermember, a lever movably mounted for engagement with said cam to rotatethe latter to an initial position relative to said dial, and a key forreleasing said drive means and moving said lever to engage and rotatesaid cam to said initial position.

4. In a page control and line indicator for typewriters having a platenrotatably mounted in a frame; the combination of an indicating dial 6mounted on said frame, a pointer member rotatably mounted adjacent tosaid dial, releasable drive means connecting said pointer member to saidplaten for rotation therewith, a heart-shaped cam fixed to said pointermember, a lever movably mounted for engagement with said cam to rotatethe latter to an initial position relative to said dial, a tooth on saidpointer member, a pawl pivotally mounted adjacent to said pointer memberto engage said tooth and limit rotation of said pointer member, and akey for releasing said drive means, moving said pawl pivotally out ofposition to engage said tooth and moving said lever to engage and rotatesaid cam to said initial position.

5. A page control and line indicator for typewriters having a platenrotatably mounted in a frame; the combination of a dial fixed to saidframe, a pointer member rotatably mounted adjacent to said dial, areleasable drive means connecting said pointer member to said platen forrotation therewith, means for returning said pointer member to aninitial position relative to said dial, a pawl member pivotally mountedadjacent to said pointer member, a shoulder on said pointer membermovable into engagement with said pawl member to limit rotation of saidpointer member, and a key for actuating said releasable drive means todisconnect said pointer member from said platen, and to rock said pawlmember away from the path of said shoulder to release said pointermember for return to said initial position.

6. The device set forth in claim 5 in which said pawl member has a fixedprojection to engage said shoulder, a movable projection spacedangularly from said fixed projection and means to move said movableprojection into and out of the path of said shoulder.

7. The device set forth in claim 5 in which said releasable gearingcomprising a first gear fixed to said platen, a second gear fixed tosaid pointer member, an idler gear movable relative to said first andsecond gears into and out of engagement with at least one of said firstand second gears to connect and disconnect said platen and said pointermember and means normally urging said idler gear into engagement withboth of said first and second gears, and said key comprising a cammember for moving said idler gear to disconnect said platen and saidpointer member.

LIN YUTANG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 844,264 Donaldson Feb. 12, 19072,460,170 Furchack Jan. 25, 1949

